Abcam, ab167727, Recombinant human CTLA4 protein (Active)

Size: 100µg
Recombinant human CTLA4 protein (Active) is a Human Fragment protein, in the 37 to 162 aa range, expressed in HEK 293 cells, with >95%, < 1 EU/µg endotoxin level, suitable for SDS-PAGE, ELISA, FuncS.
Key facts
Purity:>95% SDS-PAGE,
Endotoxin level:< 1 EU/µg,
Expression system:HEK 293 cells,
Tags:His tag C-Terminus,
Applications:SDS-PAGE, ELISA, FuncSSee reactivity dataSee the reactivity data table below for information on validated species and application combinations.,
Biologically active:Yes,
Biological activity:Measured by its binding ability in a functional ELISA. Immobilized Human B7-1, Fc Tag (ab173993) at 2μg/mL (100 μL/well) can bind ab167727 with a linear range of 0.16-2.56 ng/mL.Measured by its binding ability in a functional ELISA. Immobilized Human B7-2, Fc Tag (ab167720) at 2μg/mL (100 μL/well) can bind ab167727 with a linear range of 1-6.4 ng/mL.Measured by its binding ability in an SPR assay. Yervoy (Ipilimumab, Human IgG1) captured on CM5 chip via anti-human IgG Fc antibodies surface, can bind ab167727 with an affinity constant of 25.7 nM.,
Accession:P16410,
Animal free:No,
Carrier free:Yes,
Species:Human,
Reconstitution:Reconstitute with sterile deionized water to a concentration of 200 µg/ml.,
Storage buffer:pH: 7.4Constituents: PBS

Properties and Storage Information:
Shipped at conditions-Blue Ice, Appropriate short-term storage duration-1-2 weeks, Appropriate short-term storage conditions-+4°C, Appropriate long-term storage conditions--20°C, Aliquoting information-Upon delivery aliquot, Storage information-Avoid freeze / thaw cycle

Supplementary Information:
This supplementary information is collated from multiple sources and compiled automatically.
CTLA-4 also known as CD152 is an immune checkpoint receptor with a molecular weight of approximately 34 kDa. This protein is expressed on the surface of T-cells especially after activation and sometimes on regulatory T-cells (Tregs). CTLA-4 competes with CD28 for binding to the same ligands CD80 and CD86 on antigen-presenting cells. Unlike CD28 which stimulates T-cell activation CTLA-4 sends inhibitory signals to downregulate immune responses. By doing this CTLA-4 helps maintain immune system homeostasis and prevents autoimmune reactions.
Biological function summary
The CTLA-4 protein functions as a critical regulator of the immune system. It interacts with CD80/CD86 in a complex that effectively transmits inhibitory signals to T-cells. CTLA-4 controls the amplitude of the initial activation of T-cells ensuring that the body's immune responses are kept under control. In regulatory T-cells CTLA-4 engagement contributes to their immunosuppressive functions through which they maintain tolerance to self-antigens and prevent overactive immune reactions.
Pathways
CTLA-4 involves itself in the adaptive immune response pathways specifically the regulation of T-cell activity. CTLA-4's interaction with CD80/CD86 modulates pathways associated with TCR (T-cell receptor) signaling. When CTLA-4 binds its ligands it recruits phosphatases such as SHP-2 that dephosphorylate signaling proteins leading to the downregulation of T-cell interaction. This pathway interaction exemplifies how CTLA-4 acts in concert with proteins like CD28 to finely tune immune responses.
CTLA-4 plays a role in autoimmune diseases and cancer. The dysregulation of CTLA-4 function can lead to autoimmune disorders where the immune system attacks the body's own tissue. In cancer tumor cells may manipulate CTLA-4 pathways to evade immune surveillance. Targeted therapies like anti-CTLA-4 antibodies such as ipilimumab have been developed to block CTLA-4 aiming to enhance the immune system’s ability to attack cancer cells. These treatments highlight the role of CTLA-4 in balancing immune activity and the potential to alter this balance for therapeutic benefit.